Patents Assigned to Prisma Skyltreklam AB
  • Driving device for driving or operating elongate display members at signs for consecutive, repeated presentation of series of images
    Patent number: 5161421
    Abstract: The present invention relates to a driving device for driving or operating elongate display members at signs for consecutive, repeated presentation of series of images, whereby said elongate display members (2) are driven through pairs of gear wheels (15, 16) having conical teeth and whereby a driving gear wheel (15) in each pair of gear wheels is provided on a drive shaft (6) and a driven gear (16) wheel in each pair is operatively connected with the elongate display member (2) to be driven.
    Type: Grant
    Filed: February 19, 1992
    Date of Patent: November 10, 1992
    Assignee: Prisma Skyltreklam AB
    Inventor: Stig E. A. Stigsson
  • Incandescent matrix display with high frequency lamp driving
    Patent number: 4894645
    Abstract: The present invention relates to an electronic sign with a number of light bulbs provided in rows and columns (so called matrix), whereby said bulbs (L) are turned on row by row or column by column (so called multiplex operation). For increasing the life of the bulbs (L), said bulbs (L) are operated by alternating current at high frequency.
    Type: Grant
    Filed: May 27, 1988
    Date of Patent: January 16, 1990
    Assignee: Prisma Skyltreklam AB
    Inventor: Lars B. G. Odlen